Bump clang to 10

Dockerfile-ubuntu1804

     apt-get -y install libssl-dev build-essential && \
     apt-get -y install vim gdb strace && \
     \
-    echo deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-9 main >> /etc/apt/sources.list && \
-    echo deb-src http://apt.llvm.org/bionic/ llvm-toolchain-bionic-9 main >> /etc/apt/sources.list && \
+    echo deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-10 main >> /etc/apt/sources.list && \
+    echo deb-src http://apt.llvm.org/bionic/ llvm-toolchain-bionic-10 main >> /etc/apt/sources.list && \
     wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add - ; \
     apt update -y && \
-    apt-get install -y clang-9 lldb-9 lld-9 && \
-    apt-get install -y libc++-9-dev libc++-9-dev && \
+    apt-get install -y clang-10 lldb-10 lld-10 && \
+    apt-get install -y libc++-10-dev libc++-10-dev && \
     \
     rm -rf /var/lib/apt/lists/*
 
     rm -rf cmake-3.16.2.tar.gz
 
 # Fix some weird linker issue CAF build runs into. (fails to link -lc++abi)
-RUN cp -prv /usr/lib/llvm-9/lib/libc++abi.so.1.0 /usr/lib/llvm-9/lib/libc++abi.so
+RUN cp -prv /usr/lib/llvm-10/lib/libc++abi.so.1.0 /usr/lib/llvm-10/lib/libc++abi.so
 
 CMD "/bin/bash"

v8pp/Makefile

 
 clean:
 	rm -rf v8pp
+	rm -rf v8
 	rm -rf out
 	rm -rf depot_tools